The health impacts of dental amalgam and alternative restorative materials: a systematic review

OBJECTIVE: Conduct a systematic review of quantitative evidence comparing the adverse health impacts of dental amalgam versus other dental restorative materials. DATA SOURCES: Bibliographic database searches, limited by a date of 2007 and English language, were supplemented by citation chasing, searches of Google Search and checking topically similar systematic reviews. STUDY SELECTION: We sought empirical studies evaluating the health impacts of materials used for direct dental restorations. Two reviewers independently conducted title and abstract and full-text screening. Data extraction and quality appraisal using the Effective Public Health Practice Project Tool were carried out by one reviewer and checked by a second. We used narrative synthesis to group studies by restorative material and health impact evaluated. CONCLUSIONS: 195 studies (245 articles) were included, with 61 studies (87 articles) prioritised for narrative synthesis. Studies evaluated a variety of health impacts for the following restorative materials: amalgam versus resin-based composite (RBC): (n = 6), amalgam only (n = 52), RBC only (n = 16), glass ionomer versus RBC (n = 3). Both amalgam and non-amalgam materials may be associated with various health impacts. However, confidence in these findings is limited due to the small quantity of direct comparative evidence and heterogeneity of outcome measures and findings within health impact categories. Findings of this review may support policy makers and researchers to identify and address future research needs. CLINICAL SIGNIFICANCE: Findings highlight what is known regarding the comparative health impacts of different restorative materials, which may inform clinical decision-making alongside consideration of international guidelines, cost, material longevity, potential environmental impacts and patient-preference.